Characterization of a novel reptilian tolloid-like gene in the pond turtle, Pseudemys scripta elegans

The Tolloid metalloproteases are pleiotropic enzymes that are important for many developmental processes. This study describes the isolation and characterization of a novel Tolloid family member from the pond turtle Pseudemys scripta elegans. The turtle Tolloid, designated tTll, is found in two forms. The first, tTlls, contains a signal sequence which may provide a mechanism for secretion. The second, tTllc, does not contain a signal sequence and is likely cytoplasmic. Sequence analysis of tTll revealed that it is most closely related to chicken Tll-2 although tTll domain structure is different. We examined the expression of tTll mRNA by real-time RT-PCR and found the highest expression in the cerebellum with lower levels in the brain stem and cortex. This expression pattern is similar to the expression of the Tolloid mouse orthologues Tll-1 and Tll-2 with highest levels of expression in the cerebellum and lower levels in the brain stem and cortex.